Palos Verdes, CA
This 0.8 mile stretch of road know as Portuguese bend is the gnarliest section of road I've ever been on. This section of land is always moving. The ground is known to and often does open up. There's a constant road crew repairing it. I've seen two foot wide cracks open up and then gone in a couple days.
The Portuguese Bend Landslide is a slow moving landslide which is located on the Palos Verdes Hills. These hills form an elongated topographic dome that rises from sea level to altitudes of more than 430 meters. The main Portuguese Bend Slide spans, at its greatest, 2,700 feet (820 m) wide and 3900 long. The regional climate is characterized by mild winters and hot summers, with an annual precipitation of 25 to 100 centimeters. Precipitation occurs primarily during the winter months.
During the late Pleistocene, the Palos Verdes hills were an offshore island. The island later became a peninsula, when the region between the island and the mainland filled with alluvial deposits from the mountain ranges near the Los Angeles basin. The Palos Verdes Hills are part of an uplifted block, with a northwest trend, bounded on the northeast by the Palos Verdes fault zone. Most of the movement along this fault is dip-slip, resulting in an uplift of about 1 km of the Palos Verdes Hills relative to the Los Angeles basin.